Discovery News: Environmental

Shuffling Species

As the climate warms, many species may no longer be comfy in their habitats and become better suited to survival at higher latitudes or higher elevations where they can escape the heat. But how is a tree species that takes decades to reproduce going to migrate fast enough to keep pace with a rapidly changing climate? What if a major city lies between a critter's old habitat and where it needs to go to survive?

We might help. That's the idea behind "assisted colonization"--deliberately moving plants or animals from places where they're doomed to places where they might survive in the future. In today's issue of Science, a group of researchers published an article saying this is an approach we should take seriously. Read an article about it at Discovery News.

It's a horrifying prospect to some conservation biologists. They point to the long list of species introduced into new habitats by humans (like moving cane toads to Australia) that have gone terribly wrong. The authors of the new report agree that some introductions would be risky and should be avoided: moving polar bears from the Arctic to Antarctica would introduce a predator of penguins and seals and likely decimate those populations.

But other introductions seem less likely to cause a disruption. Most would be regional moves, not inter-continental. The authors point out that staghorn corals currently live over a range of latitudes and that those at low latitudes can tolerate higher temperatures than the ones further from the equator. Moving low-latitude coral into higher latitudes where cold-adapted corals are already dying off is unlikely to cause a problem, the authors argue.

The researchers discuss assisted colonization as a way to save species from extinction, but there might be other motivations.

For instance, here in Minnesota, we are at the southern tip of the spruce-fir forest range, which is likely to retreat into Canada in a warming climate, and our deciduous forests face threats, too. But having forests in the state is a big part of its identity. Can we be happy knowing that the forests exist to the north and learn to live without them here? Or, should we bring in trees from further south that will thrive in our new climate and keep us under a forest canopy?

It's not just a psychological issue: forests contribute to our industrial and recreational economy, so people may be reluctant to let the woods give way to savanna. Check out an earlier post about a conference here where they discussed the topic.

What do you think? Is this a good idea? When would you be willing to give a species a helping hand? Or, should we let nature take its course... whatever that means in today's world?

(Image: Flickr user *Micky, some rights reserved)

A Test

Here's an awareness test to try for fun. You can check out the home site here. If you're interested in the subject, here's a related post.

More Math at $4 a Gallon

I wrote a couple of weeks ago about one way that $4 a gallon gasoline might get us looking at things differently.

It is interesting to see stories emerging about other ways that fuel at $4 a gallon is causing changes.

First, Reuters had a story late last week about how home buyers are abandoning the 'burbs in favor of cities, partly driven by the higher fuel prices. The article mentions a survey of realtors, 80 percent of whom reported that higher fuel costs are making buyers more interested in living in cities.

The New York Times ran a story a couple of weeks ago with a similar message. It says:

In 2003, the average suburban household spent $1,422 a year on gasoline, according to the Bureau of Labor Statistics. By April of this year -- when gas prices were about $3.60 a gallon-- the same household was spending $3,196 a year, more than doubling consumption in dollar terms in less than five years.

Meanwhile high oil prices effect more than just fuel. Petroleum provides the raw materials for making plastics, paints, adhesives, soaps, fibers, pharmaceuticals and more. Just as people are looking for alternatives to using petroleum for fuel, others are trying to obtain the carbon molecules necessary to make this array of products from renewable sources.

Plastic made from corn is one example, and DuPont is making a fiber that comes partly from corn that it is using in carpets.

Of course, the expense of these alternative products has been an obstacle, because commodity chemicals derived from oil have been cheap, cheap relative to developing new, bio-based materials. But, as a Cargill executive told me when I spoke with him more than a year ago, "When you have 75 dollar a barrel oil, a lot of things can happen."

That threshold seems a quaint memory now, and the chemical industry is feeling the heat. Dow announced price hikes of up to 25 percent on commodity chemicals a couple of weeks back.

So, by the executive's estimation, bio-based processes ought to be looking pretty good. And, one researcher told me, because the amount of carbon needed for chemicals is just a teeny trickle compared with what's needed for fuels, sending some biomass to chemical processes to make plastics and other non-fuel applications should not create the competition for food that we're seeing with corn-derived ethanol and other biofuels.

(Image: Flickr user KB35, some rights reserved.)

Humpback Wisdom

Check out today's story at Discovery News explaining how seemingly odd bumps across the front of humpback whale fins allow the whales to make the tight turns necessary to surround their herring prey before rising from beneath, mouths agape, to swallow as many as they can.

I was amazed to learn that the whales encircle the fish and release air bubbles that act like a cage the fish won't cross before moving in for the kill.

Above is a great video showing the hunt.

Also, take a look at the gorgeous video on the website for WhalePower--a company that is capitalizing on these bumps in making better wind turbines and fans--to get a nice look at the fins and some lovely views of swimming whales. Guaranteed to make you feel more relaxed.

Antarctic Wildlife Feels the Heat

Today at Discovery News we reported on work by three researchers who study different aspects of the Antarctic ecosystem, and who decided to get together and tell the combined story of the changes they've seen over the last two or three decades as a result of climate change.

We thought we'd post it here so you could have your say. Do you care about what's happening in Antarctica? Are you ready to start marching for the penguins? What strikes you about the researchers' findings?

Also, stay tuned at the end of the post for some extra tidbits that didn't fit in the original story.

(Photo: Juvenile krill, Jim McClintock)

At Antarctic Peninsula, Fast Change
Jessica Marshall, Discovery News

 

July 10, 2008 -- From the tiny phytoplankton living under the ice to the penguins at the top of the food chain, the ecosystem of the Antarctic Peninsula is changing fast, driven by warming waters and a loss of sea ice.

Three researchers who have spent decades studying Antarctica's denizens paint a picture of interconnected changes at the bottom of the Earth that are changing the ecology over just decades after some 30 million years of relative isolation.

"The changes are profound," said Hugh Ducklow of the Marine Biological Research Laboratory in Woods Hole, Mass.

He and colleagues James McClintock of the University of Alabama at Birmingham and William Fraser of Polar Oceans Research Group in Sheridan, Mont. compiled their findings from studying different aspects of the Antarctic ecosystem in an article in the current issue of American Scientist.

Nowhere on Earth is climate change happening faster than on the neck of land stretching north from the Antarctic continent more than 900 miles toward South America. The average midwinter temperature on the Antarctic peninsula has increased more than 10 degrees Fahrenheit since 1950, five times the global average.

The changes the researchers see begin at the base of the food web, with phytoplankton -- tiny photosynthetic organisms that, in Antarctica, are evolved to live in the sea ice. As the extent of sea ice has decreased, so has the amount of phytoplankton.

"Sea ice is not just ice," Ducklow said. "It's a habitat for organisms."

Indeed, juvenile krill, tiny shrimplike organisms that serve as the main food source for Adélie penguins and baleen whales, graze on the phytoplankton under the sea ice.

"Juvenile forms of krill are not as strong swimmers as adults," Ducknow said "By congregating on the underside of the ice, they get a shelter from predators, and it's where the food is."

Krill have been declining for decades, the authors note, although sea ice decline may not be the only reason.

With less krill to feed on, organisms at the top of the food chain like Adélie penguins suffer. Their populations have been decreasing in the central and northern Antarctic peninsula.

The Adelie penguins also rely on the sea ice directly. In winter, they use the sea ice to get out to hotspots of food. As this shrinks, their food will be too far away to swim to.

In contrast, two related species, the gentoo and chinstrap penguins, do not rely on sea ice for winter feeding. Their populations are rising on the Peninsula.

Meanwhile, another Antarctic community is poised to change because of rising sea temperatures.

Since the Antarctic Peninsula separated from South America 25 to 35 million years ago, Antarctica has been encircled by the Antarctic Circumpolar Current, a clockwise roundabout current that holds cold water near the continent and isolates it from the rest of the ocean.

Crabs and other predators that get prey by cracking shells with strong forces were excluded from the region once the current was established, because they cannot survive at such cold temperatures.

Without such predators to guard against, animals like snails and clams in Antarctica evolved delicate, thin shells. But as the ocean warms, crab predators may move in and have defenseless prey to capitalize on. A colony of king crabs was recently found in deeper waters off the peninsula.

"It's only a matter of time before they can move up into even shallower water," said lead author McClintock, who studies Antarctica's invertebrates. "When crabs get into those communities of clams and snails and brachiopods, they are going to be history."

McClintock notes that the reproductive cycle of invertebrates is also closely tied to temperature, and warming may lead to larvae hatching out of sync with the availability of their plankton food supply.

But, he adds, kelp-like macroalgae are likely to thrive with the greater availability of sunlight thanks to reduced sea ice. And jellyfish will probably also increase in number.

What is clear is that these populations are shifting fast in relation to one another, and the ecosystem that emerges will be different from the one that has existed in isolation for millions of years.

"People say, why Antarctica? Who cares about that?" Ducklow said. "It's a canary in the coal mine. We're seeing things happen rapidly there. It's a good wakeup call for us that there is climate change, and ecosystems really are responding to it."

******************************************

Now, here's the extra bit that I'll call

Amazing Antarctic Facts

• The reason that crabs have heretofore been unable to survive in Antarctic waters is that they cannot expel magnesium from their bloodstream. Magnesium acts as a narcotic whose effect is enhanced at low temperatures. So, until now, any crabs that decided to go strolling in too-chilly waters became immobilized and died.
• Another species that is threatened by changing sea ice is the Waddell seal. Female adult seals get a private, predator-protected birthing room by using their ice-chipping teeth to scratch open a hole in the sea ice from underneath. They pop through the hole onto the surface when they're ready to pop out their young. According to McClintock, "The price they pay for these teeth is that over the years they wear down the teeth and they starve." They live about half as long as other seals, he said, but more of their young survive.
• About 70 percent of Antarctic species are found nowhere else.
• The sea ice in midwinter is about as big as the lower 48 U.S. states, but with a lot fewer Starbucks.
• Antarctic ice holds almost 2/3 of Earth's freshwater.
• Climate change has brought more snowstorms to the Peninsula. These have also harmed Adélie penguins. When it snows in spring, the nests can flood, killing eggs and hatchlings.
• If warming trends continue, the average midwinter temperature will be above freezing (for seawater) by mid-century. Sea ice will no longer form.

Smog Blog

Wildfires have been ripping through the west, and while they endanger homes and may or may not be good for the natural habitats they burn, they are definitely bad for the air quality.

The Smog Blog tracks air quality nationwide on a daily basis with satellite data, lidar, EPA pollution-monitoring networks, and more, compiled by the University of Maryland, Baltimore County Atmospheric Lidar Group. The team provides lots of maps showing clouds, smoke, particle levels, ozone levels, etc.

In recent days the emphasis has been on the wildfires in California. Plumes of smoke are easily seen from satellite images. They suggest the huge scale of the fire, but don't do justice to the havoc much closer to the ground.

Check out the maps and the air quality near you.

 

(Image: Measurements of particles < 2.5 microns shown over California. Maroon points near Auburn, Sacramento, Roseville-Rocklin and Bakersfield show hazardous levels, overlaid on true color satellite image. Image obtained from the U.S. Air Quality Smog Blog.)

Meadow Prophecy

Last week I interviewed John Harte of the University of California at Berkeley's Energy and Resources Group for the Discovery News feature I wrote on climate change.

I had interviewed him several years before, when I wrote an article about a long-term experiment he's doing in the Rocky Mountains to understand how climate change will affect ecosystems. Since 1991 he's been heating patches of the ground in a meadow in the Rocky Mountains and observing how the numbers and types of plants in the heated plots vary compared with unheated control plots.

He found that forbs, flowering plants like daisies and other wildflower-like species, were reduced by up to two-thirds in the warmed plots, while sage thrived. Soil dried out by 15-20 percent, snow melted 2 weeks earlier, and soil temperatures rose by 2 degrees Celsius.

I asked Harte what it's like to do an experiment on warming now that things are warming up in the control plots, too.

"From 2000-2005, the snowpack was very, very low," Harte said. "This led to early snow melt, and conditions in our control plots that resemble what the heated plots were subject to in the early 1990s. Sure enough, the control plots responded the same way. The carbon levels in the soil dropped."

The findings show that the heating experiments generated good predictions. "It was nature imitating science," he said.

(Image: John Harte, University of California, Berkeley)

Does a Dairy Hormone Make Milk Greener?

Green-minded eating of animal products just keeps getting trickier. A study published Monday in the Proceedings of the National Academy of Sciences says that cows given the hormone somatotropin to boost their milk production require less energy and release less methane to produce the same amount of milk as cows not given the hormone, commonly abbreviated on milk cartons as rbST.

The authors claim that 1 million cows on rbST save the greenhouse gas equivalent of taking 400,000 cars off the road, compared with the emissions from untreated cows necessary to make an equivalent amount of milk. The savings come largely because fewer cows need less food, which requires less ground to grow it on.

But Michael Hanson of the Consumers Union in New York told news outlets (here and here) that assuming  a cow making more milk can get by on the same amount of food as an untreated cow is unrealistic. Accounting for increased food needs would remove much of the gain suggested by the authors, he said.

One of the study's authors works for Monsanto, who makes rbST under the name Posilac, and another is a Monsanto consultant.

What to do? Will you dump the organic milk to save the planet or will your milk moustache remain rbST-free?

(Image: Flickr user karlfrankowski. Some rights reserved.)

Climate Scientists Talk Serious

We thought we'd post today's Discovery News story--which presents climate scientists' assessment of where we stand with climate change--here at EnvironMental Case, so you could weigh in and tell us what you think. Are you worried, very worried? Here's the story:

The Time Is Now, Climate Experts Warn

Jessica Marshall, Discovery News

June 27, 2008 -- Earlier this week, renowned NASA climate scientist James Hansen warned Congress of the dangers of climate change, exactly 20 years after he did so for the first time.

The message he delivered was almost the same as it was in 1988, but there was one key difference: "The difference is that now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb," he said.

Hansen's message painted a stark and urgent picture of a world already past the point where significant damage would occur. Discovery News wanted to know if other scientists shared his view. Are we really in for it and at what point? What are our options for avoiding the worst?

Earth's Carbon Budget

Hansen argued this week that the "safe level of atmospheric carbon dioxide is no more than 350 ppm (parts per million), and it may be less." This recommended level is less than the amount currently in the atmosphere -- 385 ppm. It may also be less than the commonly discussed stabilization target of 3.6 degrees Fahrenheit (2 degrees Celsius) of temperature increase, which probably corresponds to an atmospheric CO2 concentration of about 350-400 ppm.

Already, he argued, arid lands are expanding, glaciers are receding, and Arctic sea ice is shrinking, driven by cycles of positive feedback, where melting leads to more warming of the exposed dark ocean water, which leads to more melting.

"As a result, without any additional greenhouse gases, the Arctic soon will be ice-free in the summer," Hansen said.

To forest ecologist Lee Frelich at the University of Minnesota, Twin Cities, Hansen's argument that a lower stabilization target is safer makes sense.

"If you look at the paleological record, in the last interglacial period 110,000 to 120,000 years ago, the world was thought to have a climate that was two degrees warmer than today," Frelich said. "The oceans were 20 to 25 feet higher, but CO2 was only 290 ppm. I've always thought that if a CO2 content of 290 could cause that, why won't it do it now? Maybe there's just a lag time."

"I'm sympathetic to a more aggressive goal," said glaciologist Jay Zwally of NASA Goddard Space Flight Center in Greenbelt, Md. "The goal that people have adopted of keeping it to a total of two degrees [Celsius] rise since the preindustrial is still going to allow enough warming that we'll have an even more significant impact than we've already seen," he said.

While other scientists agree that 350 ppm is a safer target that increases the likelihood we will avoid many of the negative effects of climate change, some also think it's unrealistic.

"Three hundred and fifty is impossible," said climatologist Stephen Schneider of Stanford University in Palo Alto, Calif. "We're going to overshoot 350 and 450 and probably 550, though I sure hope not."

Schneider's hope is that while it might still be 20 years before actions to reduce CO2 emissions really have an effect, innovations over the next two decades will make it possible to dramatically reduce emissions.

"My cynical scenario is that there will be more Katrinas, massive fires, melting of the Arctic, and people will say, 'Oh my God, what have we done. We'd better undo this,'" he said. Such catastrophes could finally spark the dramatic change that's needed, he suggests, if we don't take action sooner of our own accord.

"I try not to talk about a threshold of two degrees," Schneider added. "At 1.8 the world is not fine. At 2.2, we don't turn into a climatic pumpkin. We just have more severe events. The object is not to get hung up on the numbers. The object is to get out there and get solutions."

Others agreed.

Nevermind the Tipping Point

"Time is of the essence here. I don't know if targets like 350 ppm are that useful," said John Harte of the University of California, Berkeley. "We can't make a regulation on something we can't control. We don't regulate temperature, and we don't even regulate the amount of CO2 in the atmosphere. However, we control what our automobiles look like. We control the efficiency of our devices. We control what our energy looks like."

"I'm not so enthused about the concept of the tipping point," he added. "My view is that we've probably passed some tipping points. We've entered some realms of irreversibility. There are probably many more, but we don't know where they are."

"We know that if we don't take action, it will be a disaster," he said. "That's all we need to know."

Whether they focused on thresholds or not, the scientists all agreed that the problem is urgent and that not doing anything will lead to disaster: rising sea levels, food shortages, spread of infectious diseases and extinctions.

Starting From Here...

Hansen argued that to achieve the target of 350 ppm, we need to put a moratorium on new coal-fired power plants and phase out burning coal without capturing and storing the carbon.

While scientists agree that coal is a huge part of the problem, they also emphasized the need to apply every available sensible strategy to address the problem.

"There seems to be an emphasis on coal and a distraction from other things we can be doing as well," NASA's Zwally said.

"Some people think that climate change is just about saving a few rare species, and it's just environmentalists making a fuss," Frelich said. "That's really not it."

"It's really about the quality of life for people," he continued. The Earth has been through many big changes before. There have been big extinctions, and new species have evolved to fill the ecosystems. It's not a big deal to the Earth's ecosystems, but it will be a really big deal for the quality of life of humans."

Frelich points out that right now the best soil for growing crops in the United States aligns ideally with the right climate for agriculture. But if the favorable climate moves north, it will be over Canada in an area where bedrock lies at the surface, stripped of soil by the last glaciation.

"If the best climate for growing crops lines up with the Canadian shield, that's an issue for people," he adds.

The scientists also pointed out that countries that tackle this most aggressively will be the winners, regardless of what other nations have committed to.

"The economic giants of the rest of this century are going to be the nations that are selling wind turbines and solar panels and efficient cars to the rest of the world," said Harte. "I would think we'd want to be the leader in that."

"Solving this problem is technologically and economically not that difficult," Harte added. "It's proving to be politically difficult."

(Image: "Wildfire Landscape" by Flickr user Clinton Steeds, some rights reserved.)

AutoMathically Challenged

Which will save you more gas, upgrading from an SUV that gets 10 miles per gallon to a car that gets 20? Or, switching a 30 mpg compact for a hybrid that gets 60 mpg (more than the Prius gets, but lets just say, for the sake of argument)?

Both are a doubling of gas mileage, and the latter is an increase of a whopping 30 mpg, so surely the second is better, right? If you think so, you’re not alone, according to a paper published yesterday in Science. But you’re also wrong.

The researchers who published the study argue that people make better decisions about fuel savings when fuel economy is presented in gallons per mile instead of miles per gallon.

Here are some numbers from the example above:

10 mpg=10 gallons per 100 miles
20 mpg=5 gallons per 100 miles

30 mpg=3.33 gallons per 100 miles
60 mpg=1.67 gallons per 100 miles

So, the savings in the first case is 5 gallons per 100 miles or about $20, while the savings in the second case is 1.67 gallons per 100 miles or about $6.70. Clearly, upgrading from a really inefficient car to something even marginally more efficient makes more of a difference than improving on an already good option.

The reason for this perhaps counterintuitive result is that as a number increases linearly, its inverse does not show a linear decrease. Check out the graph above: it’s clearly not a straight line. It also highlights the authors’ point that the greatest gains in gallons saved come from changes at the lowest miles per gallon, so we really need to lop off the left part of the curve.

Why does such simple math deserve a Science paper? The authors showed that most people don’t get this relationship.

They asked one group of students which choice would save more gas: to replace a fleet of cars getting 15 mpg with vehicles getting 19 mpg, or to replace an equal number of cars getting 34 mpg with ones getting 44 mpg. Seventy-five percent of students picked the latter.

Another group was given the same choice but with the information also presented in gallons per mile. This time, 65 percent of students made the right choice: choosing to replace the first group of cars.

Maybe $4 a gallon gas (that’s 0.25 gallons per dollar, by the way) will at least be good for our math skills.